JP7179448B2 - X-ray diagnostic equipment - Google Patents

Description

An embodiment of the invention relates to an X-ray diagnostic apparatus.

2. Description of the Related Art Conventionally, in an examination using an X-ray diagnostic apparatus, there are cases where a region of interest is observed with high resolution while observing a wide area of a subject from a bird's-eye view. In recent years, X-ray diagnostic equipment used for such examinations has, for example, a first detector with a large field of view that employs a TFT (Thin Film Transistor) array and a first detector that uses a CMOS (Complementary Metal Oxide Semiconductor). There is known an X-ray diagnostic apparatus equipped with a second detector having a smaller field of view than the first detector and a finer pixel pitch.

U.S. Patent Application Publication No. 2015/0003584

A problem to be solved by the present invention is to provide an X-ray diagnostic apparatus capable of improving image quality.

An X-ray diagnostic apparatus according to an embodiment includes a first X-ray detector, a second X-ray detector, and a corrector. The first X-ray detector outputs a first signal based on X-rays emitted from the X-ray tube. A second X-ray detector outputs a second signal based on the X-rays in parallel with the first X-ray detector. The correction unit generates first X-ray image data generated from a first signal output from the first X-ray detector and a second signal output from the second X-ray detector In the obtained second X-ray image data, one X-ray image data is used to correct the other X-ray image data.

FIG. 1 is a diagram showing an example of the configuration of an X-ray diagnostic apparatus according to the first embodiment. 2A is a diagram illustrating an example of the configuration of an X-ray detector according to the first embodiment; FIG. 2B is a diagram illustrating an example of the configuration of the X-ray detector according to the first embodiment; FIG. FIG. 3 is a diagram for explaining an example of correction processing by the correction function according to the first embodiment. FIG. 4 is a diagram for explaining an example of pixel size correction by the correction function according to the first embodiment. FIG. 5 is a flow chart showing the processing procedure of the X-ray diagnostic apparatus according to the first embodiment. FIG. 6A is a diagram for explaining an example of correction processing by a correction function according to the second embodiment; FIG. 6B is a diagram for explaining an example of correction processing by a correction function according to the second embodiment; FIG. 7 is a flow chart showing the processing procedure of the X-ray diagnostic apparatus according to the second embodiment. FIG. 8 is a diagram for explaining an example of scattered radiation correction by the correction function according to the third embodiment. FIG. 9 is a flow chart showing the processing procedure of the X-ray diagnostic apparatus according to the third embodiment. FIG. 10 is a flow chart showing the processing procedure of the X-ray diagnostic apparatus according to the third embodiment.

Hereinafter, embodiments of an X-ray diagnostic apparatus will be described in detail with reference to the accompanying drawings. Note that the X-ray diagnostic apparatus according to the present application is not limited to the embodiments shown below.

(First embodiment)
First, the overall configuration of the X-ray diagnostic apparatus according to the first embodiment will be described. FIG. 1 is a diagram showing an example of the configuration of an X-ray diagnostic apparatus 100 according to the first embodiment. As shown in FIG. 1, an X-ray diagnostic apparatus 100 according to the first embodiment includes a high voltage generator 11, an X-ray tube 12, an X-ray diaphragm 13, a top plate 14, a C-arm 15, X-ray detector 16, C-arm rotation/movement mechanism 17, top plate movement mechanism 18, C-arm/top plate mechanism control circuit 19, aperture control circuit 20, processing circuit 21, input circuit 22, It has a display 23 , an image data generation circuit 24 , a storage circuit 25 and an image processing circuit 26 .

In the X-ray diagnostic apparatus 100 shown in FIG. 1, each processing function is stored in the storage circuit 25 in the form of a computer-executable program. The C-arm/top plate mechanism control circuit 19, the diaphragm control circuit 20, the processing circuit 21, the image data generation circuit 24, and the image processing circuit 26 read and execute programs from the storage circuit 25, thereby corresponding to each program. It is a processor that realizes functions. In other words, each circuit with each program read has a function corresponding to the read program.

In addition, the term "processor" used in the above description includes, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an application specific integrated circuit (ASIC), a programmable logic device ( For example, it means circuits such as Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA). The processor realizes its functions by reading and executing the programs stored in the memory circuit. It should be noted that instead of storing the program in the memory circuit, the program may be directly installed in the circuit of the processor. In this case, the processor implements its functions by reading and executing the program embedded in the circuit. Note that each processor of the present embodiment is not limited to being configured as a single circuit for each processor, and may be configured as one processor by combining a plurality of independent circuits to realize its function. good.

The high voltage generator 11 generates a high voltage under the control of the processing circuit 21 and supplies the generated high voltage to the X-ray tube 12 . The X-ray tube 12 uses the high voltage supplied from the high voltage generator 11 to generate X-rays.

The X-ray diaphragm 13 narrows down the X-rays generated by the X-ray tube 12 so that the region of interest of the subject P is selectively irradiated under the control of the diaphragm control circuit 20 . For example, the X-ray diaphragm 13 has four slidable diaphragm blades. The X-ray diaphragm 13 narrows down the X-rays generated by the X-ray tube 12 by sliding these diaphragm blades under the control of the diaphragm control circuit 20 and irradiates the subject P with the X-rays. In addition, the X-ray diaphragm 13 has an additional filter for adjusting radiation quality. Additional filters are set, for example, depending on the inspection. The top board 14 is a bed on which the subject P is placed, and is arranged on a bed (not shown). Note that the subject P is not included in the X-ray diagnostic apparatus 100 .

The X-ray detector 16 detects X-rays emitted from the X-ray tube 12 and transmitted through the subject P. FIG. For example, the X-ray detector 16 has detection elements arranged in a matrix. Each detection element converts the X-rays that have passed through the subject P into an electric signal, accumulates the electric signal, and transmits the accumulated electric signal to the image data generation circuit 24 . Here, the X-ray detector 16 according to this embodiment has a plurality of detectors with different pixel pitches (different pixel sizes), and the plurality of detectors detect the X-rays that have passed through the subject P. . 2A and 2B are diagrams showing an example of the configuration of the X-ray detector 16 according to the first embodiment. Here, FIGS. 2A and 2B show longitudinal sectional views of the X-ray detector 16. FIG. Also, the image shown in FIG. 2B is a conceptual diagram.

For example, the X-ray detector 16 has a first photodetector 16a, a second photodetector 16b, and a scintillator 16c, as shown in FIG. 2A. A first detector is composed of the first photodetector 16a and the scintillator 16c, and a second detector is composed of the second photodetector 16b and the scintillator 16c.

The scintillator 16c converts the X-rays emitted from the X-ray tube 12 into light. The first photodetector 16a includes, for example, a two-dimensional image sensor employing a TFT (Thin Film Transistor) array made of amorphous silicon, detects light converted by the scintillator 16c, and outputs an electrical signal. do. The second photodetector 16b includes, for example, a two-dimensional image sensor employing a CMOS (Complementary Metal Oxide Semiconductor) transistor, detects light converted by the scintillator 16c, and outputs an electrical signal. The electrical signal output by the first photodetector 16a is hereinafter referred to as the first electrical signal, and the electrical signal output by the second photodetector 16b is referred to as the second electrical signal.

Thus, the scintillator 16c is shared by the first photodetector 16a and the second photodetector 16b. In other words, the X-ray detector 16 shares the scintillator 16c that converts the X-rays emitted from the X-ray tube 12 into light, and detects the light converted by the scintillator 16c to output an electrical signal. It has a first photodetector 16a and a second photodetector 16b. Then, the first photodetector 16a and the second photodetector 16b output electric signals simultaneously detecting the light converted by the scintillator 16c. That is, the first photodetector 16 a outputs a first signal based on the X-rays emitted from the X-ray tube 12 . Also, the second photodetector 16b outputs a second signal based on X-rays in parallel with the first photodetector 16a.

Also, as shown in FIG. 2A, the first photodetector 16a and the second photodetector 16b each have a plurality of elements that constitute a pixel unit. Each of these elements converts a fluorescent image obtained by incident X-rays into an electrical signal and stores it in a photodiode (PD). The example of FIG. 2A illustrates the case where the first photodetector 16a has eight elements in one row and the second photodetector 16b has eight elements in one row.

Here, the pixel size of each element of the second photodetector 16b is smaller than the pixel size of each element of the first photodetector 16a. That is, the pixel pitch of each element of the second photodetector 16b is finer than the pixel pitch of each element of the first photodetector 16a. In the example shown in FIG. 2A, the pixel size of each element of the first photodetector 16a corresponds to the pixel size of two elements of the second photodetector 16b. That is, in the XY plane of the X-ray detector 16, one element of the first photodetector 16a corresponds to four elements of the second photodetector 16b. Therefore, the second photodetector 16b has higher resolution than the first photodetector 16a.

Also, the first photodetector 16a has a wider field of view than the second photodetector 16b. In other words, the size of the second photodetector 16b overlaps with a part of the detection area of the first photodetector 16a. Accordingly, the second photodetector 16b collects a high resolution X-ray image in the region that overlaps with the first photodetector 16a. For example, as shown in FIG. 2B, the first detector composed of the scintillator 16c and the first photodetector 16a collects a first X-ray image I1 with a wide field of view. On the other hand, the second detector composed of the scintillator 16c and the second photodetector 16b overlaps the area in the first X-ray image I1, and compared with the first X-ray image I1, A second X-ray image I2 with a narrow field size and high resolution is acquired.

Here, in the X-ray diagnostic apparatus 100, the X-ray diaphragm 13 has four diaphragm blades, and these diaphragm blades are slid under the control of the diaphragm control circuit 20 so that the X-ray irradiation area is can be adjusted. For example, in the X-ray diagnostic apparatus 100, four diaphragm blades in the X-ray diaphragm 13 are arranged parallel to each side of the first photodetector 16a and the second photodetector 16b. The X-ray irradiation area is adjusted by sliding with the

Returning to FIG. 1 , C-arm 15 holds X-ray tube 12 , X-ray diaphragm 13 and X-ray detector 16 . The C-arm 15 rotates at high speed like a propeller around the subject P lying on the tabletop 14 by a motor provided in a support section (not shown). Here, the C-arm 15 is rotatably supported about XYZ axes, which are three orthogonal axes, and is individually rotated about each axis by a drive unit (not shown). The X-ray tube 12 , the X-ray diaphragm 13 , and the X-ray detector 16 are arranged to face each other with the subject P sandwiched by the C-arm 15 . In FIG. 1, the case where the X-ray diagnostic apparatus 100 is a single plane is described as an example, but the embodiment is not limited to this, and may be a biplane.

The C-arm rotation/movement mechanism 17 is a mechanism for rotating and moving the C-arm 15 . The C-arm rotation/movement mechanism 17 can also change the SID (Source Image receptor Distance), which is the distance between the X-ray tube 12 and the X-ray detector 16 . The C-arm rotating/moving mechanism 17 can also rotate the X-ray detector 16 held by the C-arm 15 . The top plate moving mechanism 18 is a mechanism for moving the top plate 14 .

The C-arm/top plate mechanism control circuit 19 controls the C-arm rotating/moving mechanism 17 and the top plate moving mechanism 18 under the control of the processing circuit 21, thereby rotating and moving the C-arm 15 and moving the top plate 14. Adjust movement. For example, under the control of the processing circuit 21, the C-arm/top plate mechanism control circuit 19 controls rotational imaging in which projection data is collected at a predetermined frame rate while rotating the C-arm 15. FIG. Under the control of the processing circuit 21 , the diaphragm control circuit 20 controls the irradiation area of the X-rays with which the subject P is irradiated by adjusting the aperture blades of the X-ray diaphragm 13 .

The image data generation circuit 24 generates projection data using the electrical signals converted from the X-rays by the X-ray detector 16 and stores the generated projection data in the storage circuit 25 . Specifically, the image data generation circuit 24 generates the first projection data from the first electrical signal output by the first photodetector 16a, and the second projection data output by the second photodetector 16b. Second projection data is generated from the two electric signals, and each generated projection data is stored in the storage circuit 25 . For example, the image data generation circuit 24 converts the first electric signal and the second electric signal received from the X-ray detector 16 into current/voltage conversion, A (Analog)/D (Digital) conversion, parallel/ A serial conversion is respectively performed to generate first projection data based on the first electrical signal and second projection data based on the second electrical signal, respectively. The image data generation circuit 24 then stores the generated first projection data and second projection data in the storage circuit 25 .

The storage circuit 25 receives and stores the projection data generated by the image data generation circuit 24 . For example, the storage circuit 25 stores first projection data based on the first electrical signal and second projection data based on the second electrical signal. The storage circuit 25 also stores the X-ray image generated by the image processing circuit 26 and volume data. The storage circuit 25 also stores programs corresponding to various functions read and executed by each circuit shown in FIG. For example, the storage circuit 25 stores a program corresponding to the correction function 211 and a program corresponding to the control function 212 which are read and executed by the processing circuit 21 .

The image processing circuit 26 generates an X-ray image by performing various image processing on the projection data stored in the storage circuit 25 under the control of the processing circuit 21, which will be described later. Alternatively, the image processing circuit 26 obtains projection data directly from the image data generation circuit 24 under the control of the processing circuit 21, which will be described later, and performs various image processing on the obtained projection data to generate an X-ray image. Generate. For example, the image processing circuit 26 generates a first X-ray image by performing image processing on first projection data based on the first electrical signal. The image processing circuit 26 also generates a second X-ray image by performing image processing on the second projection data based on the second electrical signal. Note that the image processing circuit 26 can also store the X-ray image after image processing in the storage circuit 25 . For example, the image processing circuit 26 executes various processes using image processing filters such as a moving average (smoothing) filter, Gaussian filter, median filter, recursive filter, and bandpass filter, and stores the processed X-ray image in a memory circuit. store in In this embodiment, the projection data generated by the image data generation circuit 24 and the X-ray image generated by the image processing circuit 26 are collectively referred to as X-ray image data. For example, the first projection data and the first X-ray image are collectively referred to as first X-ray image data. Similarly, the second projection data and the second X-ray image are collectively referred to as second X-ray image data.

Further, the image processing circuit 26 reconstructs reconstruction data (volume data) from the projection data collected by the rotation imaging. For example, the image processing circuit 26 reconstructs first reconstruction data from first projection data acquired by rotational imaging. Also, the image processing circuit 26 reconstructs second reconstruction data from the second projection data acquired by rotational imaging. The image processing circuit 26 then stores the reconstructed volume data in the storage circuit 25 . Furthermore, the image processing circuit 26 generates a three-dimensional image from the volume data. For example, the image processing circuit 26 generates a volume rendering image or an MPR (Multi Planar Reconstruction) image from the volume data. The image processing circuit 26 then stores the generated three-dimensional image in the storage circuit 25 .

The input circuit 22 includes a trackball, a switch button, a mouse, a keyboard, etc. for setting a predetermined area (for example, a region of interest such as a region of interest), a foot switch for performing X-ray irradiation, etc. realized by The input circuit 22 is connected to the processing circuit 21 , converts an input operation received from an operator into an electric signal, and outputs the electric signal to the processing circuit 21 . The display 23 displays a GUI (Graphical User Interface) for receiving instructions from the operator, various images generated by the image processing circuit 26, and X-ray images generated under the control of the processing circuit 21. .

The processing circuit 21 controls the operation of the X-ray diagnostic apparatus 100 as a whole. Specifically, the processing circuit 21 executes various processes by reading out from the storage circuit 25 and executing a program corresponding to the control function 212 for controlling the entire apparatus. For example, the control function 212 controls the high voltage generator 11 in accordance with an operator's instruction output from the input circuit 22 and adjusts the high voltage supplied to the X-ray tube 12 to irradiate the subject P. control the amount of X-rays applied and ON/OFF. Further, for example, the control function 212 controls the C-arm/top plate mechanism control circuit 19 according to the operator's instructions, and adjusts the rotation and movement of the C-arm 15 and the movement of the top plate 14 . Further, for example, the control function 212 controls the aperture control circuit 20 in accordance with an operator's instruction, and adjusts the opening degree of the aperture blades of the X-ray aperture 13 so that the X-rays irradiated to the subject P are controlled. control the irradiation area of

In addition, the control function 212 controls image data generation processing by the image data generation circuit 24, image processing by the image processing circuit 26, analysis processing, and the like, according to instructions from the operator. The control function 212 also controls the display 23 to display a GUI for receiving instructions from the operator, an image stored in the storage circuit 25, and the like. Further, for example, the correction function 211 controls correction processing by an image processing filter by the image processing circuit 26, and the like.

As shown in FIG. 1, the processing circuit 21 according to the first embodiment performs the correction function 211 and the control function 212 described above, the details of which will be described later. Note that the correction function 211 is an example of a correction unit in the scope of claims. Also, the control function 212 is an example of a control unit in the claims.

The overall configuration of the X-ray diagnostic apparatus 100 has been described above. With such a configuration, the X-ray diagnostic apparatus 100 according to this embodiment can improve image quality. Specifically, the X-ray diagnostic apparatus 100 collects X-ray images using the first photodetector 16a and the second photodetector 16b with different pixel sizes, and The image quality is improved by correcting the X-ray image acquired by the other photodetector using the X-ray image acquired by the other photodetector. Hereinafter, in the first embodiment, by correcting the second X-ray image collected by the second photodetector 16b with the first X-ray image collected by the first photodetector 16a, A case of improving the image quality of the second X-ray image while suppressing an increase in exposure dose will be described.

As described above, in the X-ray detector 16 having the first photodetector 16a and the second photodetector 16b, the X-ray emitted from the X-ray tube 12 is converted into light by the scintillator 16c, One photodetector 16a and a second photodetector 16b simultaneously detect the light converted by the scintillator 16c and output an electrical signal. That is, the light detected by the first photodetector 16 a and the second photodetector 16 b is based on one X-ray irradiation emitted from the X-ray tube 12 .

Here, in an X-ray image, if the amount of incident X-rays does not change, the smaller the pixel size of the photodetector, the smaller the number of X-ray photons that contribute to the signal of one pixel. increases. For example, in the X-ray detector 16, the number of photons incident on each pixel of the second photodetector 16b having a smaller pixel size is smaller than the number of photons incident on each pixel of the first photodetector 16a. , the second X-ray image is noisier compared to the first X-ray image. Therefore, when the X-ray dose is controlled such that the first X-ray image acquired by the first photodetector 16a has a desired Signal to Noise Ratio (SNR), the second photodetector The SNR of the second X-ray image acquired by 16b is lower than the desired SNR.

On the other hand, if the X-ray dose is controlled so that the second X-ray image collected by the second photodetector 16b has a desired SNR, the first photodetector 16a will detect X-rays more than necessary and sufficient. Because of the dose, there is still room for reducing the exposure dose of the subject P.

Therefore, the X-ray diagnostic apparatus 100 according to the first embodiment controls the X-rays so that the first X-ray image has a desired SNR, while controlling the first X-ray image with respect to the second X-ray image. By performing correction processing using the line image, the image quality of the second X-ray image is improved while suppressing an increase in exposure dose. An example of processing by the X-ray diagnostic apparatus 100 according to the first embodiment will be described below.

The correction function 211 according to the first embodiment includes first X-ray image data generated from a first signal output from the first photodetector 16a and output from the second photodetector 16b In the second X-ray image data generated from the second signal, one X-ray image data is used to correct the other X-ray image data. Specifically, for the first X-ray image data and the second X-ray image data, the correction function 211 performs image processing such that one X-ray image data is used to correct the other X-ray image data. Controls circuit 26 . The control of the correction function 211 for the image processing circuit 26 will be described below.

For example, the correction function 211 converts the first X-ray image data generated from the first electrical signal output from the first photodetector 16a to the second X-ray image data output from the second photodetector 16b. Correction is performed using the second X-ray image data generated from the electrical signal. For example, the correction function 211 weights each of the first X-ray image data and the second X-ray image data according to the image characteristics of the corrected first X-ray image data, and after weighting are added to correct the first X-ray image data. That is, the correction function 211 causes the image processing circuit 26 to perform averaging processing on the X-ray image data collected from each detector.

Here, the correction function 211 performs not only averaging processing between X-ray image data collected from each detector, but also averaging processing between X-ray image data in the time direction and addition in the spatial direction. Averaging can be combined and executed. A case where these addition/averaging processes are executed in combination will be described below with an example. FIG. 3 is a diagram for explaining an example of correction processing by the correction function 211 according to the first embodiment. Here, in FIG. 3, the time axis is shown in the horizontal direction, the upper stage shows the X-ray pulse with time to the first photodetector 16a, and the lower stage shows the time-dependent X-ray pulse to the second photodetector 16b. An X-ray pulse is shown. Also, the area of the rectangle indicating the X-ray pulse in FIG. 3 indicates the X-ray dose. Note that FIG. 3 shows a case where the X-ray dose is controlled so as to obtain an appropriate SNR in the first photodetector 16a having a large pixel size. That is, in FIG. 3, the second X-ray image collected by the second photodetector 16b having a small pixel size is a noisy image.

For example, as shown in FIG. 3, when an X-ray pulse is emitted from the X-ray tube 12 at a predetermined frequency and detected by each detector, X-ray image data is generated based on each X-ray pulse. be done. For example, the image data generation circuit 24 generates first projection data based on each X-ray pulse detected over time by a first detector composed of a scintillator 16c and a first photodetector 16a. do. Then, the image processing circuit 26 generates first X-ray images from the first projection data generated by the image data generating circuit 24, respectively. For example, the image processing circuit 26 sequentially generates first X-ray images L _t-2 to L _t+1 based on each X-ray pulse, as shown in FIG.

Similarly, the image data generation circuit 24 generates second projection data based on each X-ray pulse detected over time by a second detector composed of a scintillator 16c and a second photodetector 16b. Generate. Then, the image processing circuit 26 generates second X-ray images from the second projection data generated by the image data generating circuit 24, respectively. For example, the image processing circuit 26 sequentially generates second X-ray images S _t-2 to S _t+1 based on each X-ray pulse, as shown in FIG.

The correcting function 211 first performs averaging processing of a plurality of first X-ray images acquired over time and a plurality of second X-ray images acquired over time, thereby obtaining each detector Arithmetic averaging processing between X-ray image data collected from , and averaging processing between X-ray image data in the time direction are executed. Thereafter, the correction function 211 performs averaging processing in the spatial direction on the corrected X-ray image generated by the averaging processing.

For example, as shown in FIG. 3, the correction function 211 applies the averaging process for _reducing the noise of the second X-ray image St to the first X-ray image _Lt-1 and the first X-ray image Lt-1. L _t and the second X-ray image S _t-1 are used. _That is, the _correction function _{211 performs} The second X-ray image S _t is corrected by performing weighting and adding.

For example, the correction function 211 executes the averaging process shown in the following formula (1). Here, "S'" in equation (1) indicates the corrected X-ray image. Also, "W(s,t)" in Equation (1) indicates the weight for the second X-ray image St, and "W(s, _t -1)" indicates the weight of the second X-ray image _St Indicates the weight for _-1 . Further, "W(L,t)" in Equation (1) indicates the weight for the first X-ray image Lt, and "W(L, _t -1)" is the weight for the first X-ray image _Lt Indicates the weight for _-1 .

That is, the correction function 211 executes correction processing of multiplying each X-ray image by a weight corresponding to each X-ray image and adding each X-ray image multiplied by the weight, as shown in Equation (1). Here, the weights used in the correction process are set so that the sum of the weights is "1", as shown in the following equation (2), for example.

As described above, the correction function 211 performs a correction process of weighting and adding each X-ray image. Here, the correction function 211 performs weighting according to the corrected image characteristics of the X-ray image data to be corrected. For example, the correction function 211 determines weights according to the _corrected image characteristics of the second X-ray image St, and multiplies each X-ray image by the determined weights. For example, the correction function 211 determines the weight according to the spatial resolution, _SNR , motion blur, etc. of the second X-ray image St after correction. An example of weight determination according to these image characteristics will be described below.

First, when emphasizing the spatial resolution, the correction function 211 determines the weight so that the X-ray image acquired by the photodetector with the large pixel size is weighted less. That is, when the second X-ray image S _t is to be corrected, the correction function 211 assigns a relatively low weight to the first X-ray image so that the corrected second X-ray image Correct the image so that it has a relatively high spatial resolution.

The second X-ray image collected by the second photodetector 16b, which has a smaller pixel size, has a higher resolution than the first X-ray image collected by the first photodetector 16a. Therefore, by reducing the weight of the first X-ray image used in the averaging process, it is possible to prevent deterioration of the spatial resolution of the corrected second X-ray image. For example, the correction function 211 compares "W (s, t)" and "W (s, t-1)" to "W (L, t)" and "W (L, t-1)" is controlled to be smaller.

Next, when emphasizing SNR, the correction function 211 determines weights so that X-ray images acquired by photodetectors with large pixel sizes are given greater weights. That is, when the second X-ray image S _t is to be corrected, the correction function 211 weights the first X-ray image relatively high so that the corrected second X-ray image Correct the image so that it has a relatively high SNR.

As described above, the second X-ray image has a lower SNR because the first X-ray image with the larger pixel size was acquired with an adequate SNR. Therefore, by increasing the weight of the first X-ray image used in the averaging process, the SNR of the corrected second X-ray image can be improved. For example, the correction function 211 compares "W (s, t)" and "W (s, t-1)" to "W (L, t)" and "W (L, t-1)" is controlled to be larger.

Next, when reducing motion blur, the correction function 211 determines weights so that the weights for past X-ray images are reduced in chronological order. That is, the correction function 211 selects an X-ray image that is chronologically earlier than the X-ray image to be corrected, among the plurality of temporal first X-ray images and the plurality of temporal second X-ray images. By applying a relatively low weight to the line image data, correction is performed so that the motion blur included in the corrected X-ray image is relatively low.

When averaging processing is performed using a plurality of X-ray images in the time direction, motion blur may be included in the X-ray image after correction. Therefore, by reducing the weight of the past X-ray image used for the averaging process, it is possible to reduce the motion blur of the corrected second X-ray image. For example, the correction function 211 compares "W(s,t)" and "W(L,t)" to "W(s,t-1)" and "W(L,t-1)" is controlled to be larger.

As described above, the correction function 211 determines weights according to the image quality characteristics of the X-ray image after correction, and performs averaging processing using the determined weights. Here, the first photodetector 16a and the second photodetector 16b have different pixel sizes. Therefore, the correction function 211 performs correction to match the pixel sizes of the first X-ray image and the second X-ray image prior to the averaging process in order to associate the pixels to be subjected to the above-described averaging process.

Specifically, the correction function 211 corrects the first X-ray image or the second X-ray image to match the smaller pixel size of the pixel size of the first photodetector 16a and the pixel size of the second photodetector 16b. After correcting one X-ray image, one X-ray image is used to correct the other X-ray image. That is, the correction function 211 corrects the first X-ray image so as to match the pixel size of the second X-ray image, and then performs the averaging process described above.

FIG. 4 is a diagram for explaining an example of pixel size correction by the correction function 211 according to the first embodiment. Here, in FIG. 4, the pixels of the first photodetector 16a and the pixels of the second photodetector 16b are shown in a grid pattern. For example, in the X-ray detector 16 according to the first embodiment, as shown in FIG. 4, one pixel of the first photodetector 16a corresponds to four pixels of the second photodetector 16b. do. Correction function 211 then performs an upsampling of the first X-ray image collected from first photodetector 16a to match the pixel size of second photodetector 16b.

For example, the correction function 211 uses a bicubic method, a bilinear method, a nearest neighbor method, or the like as a resampling method when performing upsampling on the first X-ray image. interpolation processing for each pixel of Thereby, the correction function 211 associates each pixel of the first X-ray image with each pixel of the second X-ray image, and performs the above-described averaging process between the associated pixels. Note that the correction function 211 may perform resolution correction such as super-resolution after executing the above-described pixel resampling. For example, the correction function 211 performs resampling on the first X-ray image and performs resolution correction on the resampled first X-ray image. After that, the correction function 211 executes the above-described averaging process using the first X-ray image after resolution correction.

As described above, when the averaging process between the X-ray image data collected from each detector and the averaging process between the X-ray image data in the time direction are executed, the correction function 211 performs the above-described addition A spatial averaging process is performed on the corrected X-ray image data generated by the averaging process. For example, the correction function 211 performs an averaging process based on the degree of similarity with surrounding pixels for each _pixel in the corrected second X-ray image St.

For example, the correction function 211 determines the weight of the pixel value of each peripheral pixel based on the degree of similarity between the target pixel to be subjected to the averaging process and the peripheral pixels. Then, the correction function 211 executes an addition/averaging process in which the pixel value of the target pixel is obtained by adding the determined weights to the respective peripheral pixels. Here, the correction function 211 increases the weight of the peripheral pixels when the similarity between the target pixel and the peripheral pixels is large. This allows the correction function 211 to further reduce noise in the corrected second X-ray image.

Returning to FIG. 1 , the control function 212 causes the display 23 to display the X-ray image on which the averaging process has been performed by the correction function 211 . For example, the control function ₂₁₂ causes the display 23 to display the second X-ray image St after correction. Here, the control function 212 can also display the first X-ray image in parallel with the _corrected second X-ray image St.

Next, processing of the X-ray diagnostic apparatus 100 according to the first embodiment will be described using FIG. FIG. 5 is a flow chart showing the processing procedure of the X-ray diagnostic apparatus 100 according to the first embodiment. Steps S101 and 105 shown in FIG. 5 are steps in which the processing circuit 21 reads a program corresponding to the control function 212 from the storage circuit 25 and executes it. Steps S102 to S104 are steps in which the processing circuit 21 reads out a program corresponding to the correction function 211 from the storage circuit 25 and executes it.

At step S101, processing circuitry 21 acquires a first X-ray image and a second X-ray image, respectively. At step S102, the processing circuit 21 performs resampling on the large pixels to fit the small pixel size. In step S103, the processing circuit 21 determines weights according to the corrected image characteristics.

In step S104, the processing circuitry 21 weights each X-ray image with the determined weight and adds them. In step S105, the processing circuitry 21 causes the display 23 to display the corrected X-ray image.

As described above, according to the first embodiment, the first photodetector 16 a outputs the first electrical signal based on the X-rays emitted from the X-ray tube 12 . The second photodetector 16b outputs a second electrical signal based on X-rays in parallel with the first photodetector 16a. The correction function 211 corrects the first X-ray image data generated from the first electrical signal output from the first photodetector 16a and the second electrical signal output from the second photodetector 16b. In the generated second X-ray image data, one X-ray image data is used to correct the other X-ray image data. Therefore, the X-ray diagnostic apparatus 100 according to the first embodiment can perform correction processing between image data acquired at the same time, thereby improving image quality.

Further, according to the first embodiment, the correction function 211 calculates the corrected image characteristics of the X-ray image data to be corrected for each of the first X-ray image data and the second X-ray image data. is weighted according to , and the weighted X-ray image data are added to correct the X-ray image data to be corrected. Therefore, the X-ray diagnostic apparatus 100 according to the first embodiment makes it possible to correct an X-ray image having desired image characteristics.

Further, according to the first embodiment, the first photodetector 16a and the second photodetector 16b generate the first electrical signal based on the X-rays emitted from the X-ray tube 12 over time. and a second electrical signal over time. The correction function 211 corrects a plurality of chronological first X-ray image data generated from the chronologically output first electrical signals, and the chronologically generated data from the chronologically output second electric signals. each of the plurality of second X-ray image data to be corrected is weighted according to the image characteristics after correction of the X-ray image data to be corrected, and the weighted X-ray image data are added. , the X-ray image data to be corrected is corrected. Therefore, the X-ray diagnostic apparatus 100 according to the first embodiment can use the X-ray images acquired over time for averaging processing, and can correct the X-ray images to improve the image quality. to

Further, according to the first embodiment, when the second X-ray image data is to be corrected, the correction function 211 assigns a relatively low weight to the first X-ray image data. , so that the corrected second X-ray image data has a relatively high spatial resolution. Therefore, the X-ray diagnostic apparatus 100 according to the first embodiment makes it possible to correct an X-ray image with an emphasis on spatial resolution.

Further, according to the first embodiment, when the second X-ray image data is to be corrected, the correction function 211 weights the first X-ray image data relatively high. , so that the corrected second X-ray image data has a relatively high signal-to-noise ratio. Therefore, the X-ray diagnostic apparatus 100 according to the first embodiment makes it possible to correct an X-ray image with an emphasis on SNR. For example, if the X-ray dose suitable for the first photodetector 16a is always taken, the second X-ray image collected by the second photodetector 16b will be a relatively noisy image. , the X-ray images collected by each detector can be used to provide images with effectively improved SNR. Therefore, as a secondary effect, it is not necessary to irradiate the second photodetector 16b with an X-ray dose suitable for the second photodetector 16b. As a result, it is possible to reduce the exposure dose of the subject.

Further, according to the first embodiment, the correction function 211 selects X-rays to be corrected from among the plurality of time-lapsed first X-ray image data and the plurality of time-lapsed second X-ray image data. By applying a relatively low weight to the X-ray image data chronologically older than the image data, correction is performed so that motion blur included in the X-ray image data after correction is relatively low. . Therefore, the X-ray diagnostic apparatus 100 according to the first embodiment makes it possible to correct an X-ray image with reduced motion blur.

Further, according to the first embodiment, the correction function 211 selects the first photodetector 16a and the second photodetector 16b so as to match the smaller pixel size. After correcting the X-ray image data, the first X-ray image data is used to correct the second X-ray image data. Therefore, the X-ray diagnostic apparatus 100 according to the first embodiment enables accurate averaging processing even between X-ray images having different pixel sizes.

(Second embodiment)
Next, a second embodiment will be described. The configuration of the X-ray diagnostic apparatus 100 according to this embodiment is basically the same as the configuration of the X-ray diagnostic apparatus 100 shown in FIG. Therefore, the following description will focus on the points that are different from the X-ray diagnostic apparatus 100 according to the first embodiment, and the same reference numerals will be given to the components that play the same roles as the components shown in FIG. detailed description is omitted.

In the above-described first embodiment, the case of irradiating the first photodetector 16a with an X-ray pulse with an X-ray dose suitable for the first photodetector 16a has been described. In the second embodiment, an X-ray pulse with an X-ray dose suitable for the first photodetector 16a and an X-ray pulse with an X-ray dose suitable for the second photodetector 16b are alternately irradiated. do.

The first photodetector 16a and the second photodetector 16b according to the second embodiment detect a first electric A signal and a second electrical signal are output over time, respectively. For example, the control function 212 alternately irradiates an X-ray pulse with an X-ray dose suitable for the first photodetector 16a and an X-ray pulse with an X-ray dose suitable for the second photodetector 16b. It controls the high voltage generator 11 . The first photodetector 16a and the second photodetector 16b generate an electrical signal based on the X-ray pulse with an X-ray dose suitable for the first photodetector 16a and an X-ray pulse suitable for the second photodetector 16b. Each alternately outputs an electrical signal based on a dose of X-ray pulses.

A correction function 211 according to the second embodiment includes a plurality of temporally-output first X-ray image data generated from temporally-output first electrical signals, and temporally-output second X-ray image data. X-ray image data based on X-rays with a relatively large dose among the plurality of time-lapse second X-ray image data generated from the electric signals of the corrected X-ray image data is given a high weighting. Correct the line image data so that it has a relatively high signal-to-noise ratio.

6A and 6B are diagrams for explaining an example of correction processing by the correction function 211 according to the second embodiment. Here, in FIGS. 6A and 6B, the time axis is shown in the horizontal direction, the upper stage of each figure shows the X-ray pulse with time to the first photodetector 16a, and the lower stage of each figure shows the second X-ray pulse. The X-ray pulses to photodetector 16b are shown over time. Also, the area of the rectangle indicating the X-ray pulse in FIGS. 6A and 6B indicates the X-ray dose.

FIG. 6A shows a case where an X-ray image based on an X-ray pulse with an X-ray amount suitable for the first photodetector 16a having a large pixel size is to be corrected. That is, at time "t", the first photodetector 16a is irradiated with an X-ray pulse having an X-ray dose suitable for the first photodetector 16a. Also, FIG. 6B shows a case where an X-ray image based on an X-ray pulse with an X-ray dose suitable for the second photodetector 16b having a small pixel size is to be corrected. That is, it shows the case where the second photodetector 16b is irradiated with an X-ray pulse having an X-ray dose suitable for time "t".

For example, the correction function 211 uses the weights "W (s, t)", "W (s, t-1)", "W (L, t)", "W (L, t -1)” is determined according to the dose of the irradiated X-rays, and the determined weight is used to perform the averaging process shown in Equation (1).

For example, as shown in FIG. 6A, the second X-ray image S _t is to be corrected, and an X-ray pulse with an X-ray dose suitable for the first photodetector 16a is irradiated at time "t". If so, the correction function 211 applies the weight "W(L,t-1)" of the first X-ray image _Lt-1 , which is an X-ray image acquired at high dose, to the weight "W(L,t-1)" of the second X-ray image Control is performed so that the weight "W(s, _t -1)" of St-1 is relatively increased.

On the other hand, as shown in FIG. 6B, the second X-ray image S _t is to be corrected, and an X-ray pulse with an X-ray dose suitable for the second photodetector 16b is irradiated at time "t". In this case, the correction function 211 calculates the weight "W(L,t)" of the first X-ray image Lt, which is an X-ray image acquired with a large dose, and the weight "W(L, _t )" of the second X-ray image _St. s, t)” is controlled to be relatively raised.

Next, processing of the X-ray diagnostic apparatus 100 according to the second embodiment will be described using FIG. FIG. 7 is a flow chart showing the processing procedure of the X-ray diagnostic apparatus 100 according to the second embodiment. Steps S201 and S205 shown in FIG. 7 are steps in which the processing circuit 21 reads a program corresponding to the control function 212 from the storage circuit 25 and executes it. Steps S202 to S204 are steps in which the processing circuit 21 reads out a program corresponding to the correction function 211 from the storage circuit 25 and executes it.

In step S201, the processing circuit 21 acquires a first X-ray image and a second X-ray image over time while changing the X-ray dose. At step S202, processing circuitry 21 performs resampling on the larger pixels to fit the smaller pixel size. In step S203, the processing circuitry 21 determines weights such that X-ray images with high doses are given relatively high weights.

In step S204, the processing circuit 21 weights each X-ray image with the determined weight and adds them. In step S205, the processing circuitry 21 causes the display 23 to display the corrected X-ray image.

As described above, according to the second embodiment, the first photodetector 16a and the second photodetector 16b detect a plurality of X-rays with different doses emitted from the X-ray tube 12 over time. Based on this, the first electrical signal and the second electrical signal are output over time. The correction function 211 corrects a plurality of chronological first X-ray images generated from the chronologically output first electrical signals, and chronologically generated from the chronologically output second electric signals. By giving a high weight to the X-ray image based on the X-ray having a relatively large dose among the plurality of second X-ray images, the X-ray image data after correction is relatively high signal pair Correct to have noise ratio. Therefore, the X-ray diagnostic apparatus 100 according to the second embodiment can increase the weight of the X-ray image with less noise, improve the SNR, and improve the image quality.

Thus, in the X-ray diagnostic apparatus 100 according to the second embodiment, when the incident dose to the second photodetector 16b is relatively insufficient (the X-ray dose to the first photodetector 16a is ), an image with effectively improved SNR can be provided by using images of both detectors when an appropriate dose is incident on the second photodetector 16b. Also, for example, by alternately irradiating each photodetector with an appropriate X-ray dose, the exposure dose of the subject can be reduced compared to the case where the second photodetector 16b is always irradiated with an appropriate dose. be able to.

(Third embodiment)
Next, a third embodiment will be described. The configuration of the X-ray diagnostic apparatus 100 according to this embodiment is basically the same as the configuration of the X-ray diagnostic apparatus 100 shown in FIG. Therefore, the following description will focus on the points that are different from the X-ray diagnostic apparatus 100 according to the first embodiment, and the same reference numerals will be given to the components that play the same roles as the components shown in FIG. detailed description is omitted.

In the third embodiment, a case where a scattered radiation image is generated from a first X-ray image collected by the first photodetector 16a and scattered radiation correction is performed will be described. Since scattered radiation leads to deterioration of contrast, the scattered radiation component is usually estimated by a method using a spatial filter or the like, and the scattered radiation component is removed. Here, when the X-ray detector 16 has a wide-field-of-view first photodetector 16a and a narrow-field-of-view second photodetector 16b, the narrow-field-of-view second photodetector 16b has , photons based on scattered rays are mixed from outside the field of view. However, in the method using the spatial filter described above, it is difficult to accurately estimate such scattered radiation components from outside the field of view only from the second X-ray image data collected by the second photodetector 16b. is.

Therefore, in the X-ray diagnostic apparatus 100 according to the third embodiment, the correction function 211 uses the first photodetector 16a, which has a wider field of view, than the first photodetector 16a and the second photodetector 16b. Scattered radiation image data is generated based on the first X-ray image data generated from the output electrical signal, and the generated scattered radiation image data is used to output by the second photodetector 16b having a narrow field of view. Scattered radiation correction is performed on the second X-ray image data generated from the electrical signals obtained. In other words, the correction function 211 estimates the scatter component using the first X-ray image data collected by the first photodetector 16a and performs scatter correction of the second X-ray image data. .

FIG. 8 is a diagram for explaining an example of scattered radiation correction by the correction function 211 according to the third embodiment. Each image shown in FIG. 8 is a conceptual diagram. For example, as shown in FIG. 8, the correction function 211 uses a first X-ray image I1 collected by the first photodetector 16a to generate a scattered radiation image showing scattered radiation components, and a second A scattered radiation corrected image I6 is generated by subtracting the scattered radiation image from the second X-ray image I2 collected by the photodetector 16b.

Here, the correction function 211 uses the first X-ray image I1 generated from the signal output by the first photodetector 16a with a wide field of view to shorten the generation time of the scattered radiation image. An area slightly wider than the field of view of the second photodetector 16b is extracted, and a scattered radiation image is generated using the extracted area. For example, as shown in FIG. 8, the correction function 211 cuts out an area slightly wider than the field of view of the second photodetector 16b from the first X-ray image I1, and generates a scattered radiation image I3 of the cut out area. . Then, the correction function 211 cuts out the scattered radiation image I4 of the region corresponding to the second X-ray image I2 in the scattered radiation image I3. Thereafter, the correction function 211 performs scattered radiation correction of the second X-ray image I2 by subtracting the scattered radiation image I4 from the second X-ray image I2.

Note that when the scattered radiation correction is also performed on the first X-ray image I1, the correction function 211 generates a scattered radiation image using the first X-ray image I1, and the first X-ray image Scatter correction of the first X-ray image I1 is performed by subtracting the scattered radiation image from I1. Here, when a scattered radiation image is generated using the first X-ray image I1, the correction function 211 cuts out a region corresponding to the second X-ray image I2 from the generated scattered radiation image, and obtains a second It may be the case of executing scattered radiation correction of the X-ray image I2. That is, the correction function 211 may generate a scattered radiation image without cutting out an area slightly wider than the field of view of the second photodetector 16b from the first X-ray image I1.

Here, if the scattered radiation correction is performed as described above, the signal components in each X-ray image may also decrease, and the SNR may decrease. Therefore, by performing the averaging process described in the first embodiment and the second embodiment on each X-ray image after executing the scattered radiation correction, the SNR that has decreased due to the scattered radiation correction can be reduced. It can be improved.

The control function 212 according to the third embodiment can also cause the display 23 to display an X-ray image after scattered radiation correction, in addition to the X-ray image after the averaging process. For example, the control function 212 can cause the display 23 to display the first X-ray image I1 and the scattered radiation corrected image I6 shown in FIG. The control function 212 can also display the first X-ray image after the scattered radiation correction and the scattered radiation corrected image I6 on the display 23 side by side.

Next, processing of the X-ray diagnostic apparatus 100 according to the third embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 and 10 are flowcharts showing processing procedures of the X-ray diagnostic apparatus 100 according to the third embodiment. Here, FIG. 10 corresponds to the process of step S302 in FIG. Steps S301, 302, and 306 shown in FIG. 9 are steps in which the processing circuit 21 reads a program corresponding to the control function 212 from the storage circuit 25 and executes it. Steps S303 to S305 shown in FIG. 9 are steps in which the processing circuit 21 reads out a program corresponding to the correction function 211 from the storage circuit 25 and executes it. Steps S3021 to S3024 shown in FIG. 10 are steps in which the processing circuit 21 reads out a program corresponding to the correction function 211 from the storage circuit 25 and executes it. Step S3025 shown in FIG. 10 is a step in which the processing circuit 21 reads a program corresponding to the control function 212 from the storage circuit 25 and executes it.

At step S301 in FIG. 9, processing circuitry 21 acquires a first X-ray image and a second X-ray image, respectively. At step S302, processing circuitry 21 performs scattered radiation correction on the first X-ray image and the second X-ray image. At step S303, processing circuitry 21 performs resampling on the large pixels to fit the small pixel size. In step S304, the processing circuitry 21 determines weights according to the corrected image characteristics.

In step S305, processing circuitry 21 weights each X-ray image with the determined weight and sums. In step S306, the processing circuitry 21 causes the display 23 to display the corrected X-ray image.

In step S3021 in FIG. 10, the processing circuitry 21 determines the cut-out size so as to be larger than the field size of the second photodetector 16b having a narrow field of view. In step S3022, the processing circuit 21 extracts an image with the determined crop size from the first X-ray image acquired by the wide-field-of-view first photodetector 16a. In step S3023, the processing circuitry 21 generates a scattered radiation image from the clipped image.

In step S3024, processing circuitry 21 performs scattered radiation correction by subtracting the scattered radiation image from the X-ray image collected by each photodetector. In step S3025, the processing circuit 21 causes the display 23 to display the scattered radiation corrected image after the scattered radiation correction.

As described above, according to the third embodiment, of the first photodetector 16a and the second photodetector 16b, the correction function 211 is output by the first photodetector 16a having a wide field of view. Scattered radiation image data is generated based on the X-ray image data generated from the electrical signal generated from the electrical signal generated from the electrical signal output by the second photodetector 16b having a narrow field of view using the generated scattered radiation image data. Scattered radiation correction is performed on the obtained second X-ray image data. Therefore, the X-ray diagnostic apparatus 100 according to the third embodiment can generate a more accurate scattered radiation image, enabling accurate scattered radiation correction of the second X-ray image data. .

Further, according to the third embodiment, the correction function 211 converts the first X-ray image data generated from the electrical signal output by the first photodetector 16a with a wide field of view to the second X-ray image data with a narrower field of view. An area wider than the field of view of the photodetector 16b is extracted, and scattered radiation image data is generated using the extracted area. Therefore, the X-ray diagnostic apparatus 100 according to the third embodiment makes it possible to shorten the time required for scattered radiation correction.

Further, according to the third embodiment, the control function 212 controls the display image based on the first X-ray image data generated from the electrical signal output by the first photodetector 16a with a wide field of view, and the scattering A display image based on the second X-ray image data after line correction is displayed in parallel. Therefore, the X-ray diagnostic apparatus 100 according to the third embodiment makes it possible to display the first X-ray image and the second X-ray image with improved image quality.

(Fourth embodiment)
Now, although the first to third embodiments have been described so far, various different modes other than the above-described first to third embodiments may be implemented.

In the above-described first to third embodiments, the cases where the second X-ray image data having a small pixel size are to be corrected have been described. However, the embodiment is not limited to this, and for example, the first X-ray image data having a large pixel size may be the correction target. When the first photodetector 16a and the second photodetector 16b share the scintillator 16c like the X-ray detector 16 and detect light respectively, the light converted by the scintillator 16c reaches the scintillator 16c. Since the light is directed to both sides, the amount of photons detected by each photodetector is reduced compared to a normal X-ray detector. That is, the amount of photons detected by the first photodetector 16a is also reduced, and the SNR may be lowered as compared with a normal X-ray detector.

Therefore, the correction function 211 performs the above-described averaging process on the first X-ray image data as a correction target. Here, even when the first X-ray image data is to be corrected, the correction function 211 performs averaging processing according to the image characteristics of the corrected first X-ray image data, as in the first embodiment. determine the weights in

Further, in the first to third embodiments, averaging processing using X-ray images at time "t" and time "t-1" has been described. However, the embodiment is not limited to this, and the number of X-ray images used for averaging processing is arbitrary.

Each component of each device illustrated in the above-described first to third embodiments is functionally conceptual, and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution/integration of each device is not limited to the illustrated one, and all or part of them can be functionally or physically distributed/integrated in arbitrary units according to various loads and usage conditions. Can be integrated and configured. Furthermore, all or any part of each processing function performed by each device can be realized by a CPU and a program analyzed and executed by the CPU, or realized as hardware by wired logic.

Further, the control method described in the above embodiments can be realized by executing a prepared control program on a computer such as a personal computer or a work station. This control program can be distributed via a network such as the Internet. In addition, this control program is recorded on a computer-readable recording medium such as a hard disk, flexible disk (FD), CD-ROM, MO, DVD, etc., and can be executed by being read from the recording medium by a computer.

As described above, according to at least one embodiment, it is possible to improve image quality.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

16 X-ray detector 16a First photodetector 16b Second photodetector 16c Scintillator 21 Processing circuit 100 X-ray diagnostic device 211 Correction function 212 Control function

Claims (10)

a scintillator that converts X-rays emitted from an X-ray tube into light;
a first X-ray detector that detects light converted by the scintillator and outputs a first signal;
a second X-ray detector sharing the scintillator with the first X-ray detector and detecting light converted by the scintillator and outputting a second signal in parallel with the first X-ray detector; a line detector;
First X-ray image data generated from the first signal output from the first X-ray detector and second generated from the second signal output from the second X-ray detector are weighted according to the spatial resolution, signal-to-noise ratio, or motion blur after correction of the X-ray image data to be corrected, and the weighted X-ray image data are added. a correction unit that corrects the X-ray image data to be corrected;
with
The first X-ray detector and the second X-ray detector generate the first signal and the second X-ray detector based on a plurality of X-rays with different doses emitted from the X-ray tube over time. signals over time,
The correction unit is generated from a plurality of chronological first X-ray image data generated from the chronologically outputted first signal and the chronologically outputted second signal Weighting for the plurality of second X-ray image data over time is determined based on doses of the plurality of X-rays, and the plurality of first X-ray image data and the plurality of second X-ray image data are weighted. An X-ray diagnostic apparatus that corrects the X-ray image data to be corrected using the image data and the weighting . The correction unit is generated from a plurality of chronological first X-ray image data generated from the chronologically output first signal and the chronologically output second signal. By giving a high weight to X-ray image data based on X-rays with a relatively large dose among the plurality of second X-ray image data over time, X-ray image data after correction is relatively 2. The X-ray diagnostic apparatus of claim 1 , wherein the X-ray diagnostic apparatus is corrected to have a high signal-to-noise ratio. The correcting unit corrects the first X-ray image data or the second X-ray image data so as to match the smaller pixel size of the pixel size of the first X-ray detector and the pixel size of the second X-ray detector. 3. The X-ray diagnostic apparatus according to claim 1, wherein said X-ray image data to be corrected is corrected after correcting said X-ray image data. The correcting unit corrects scattered radiation based on X-ray image data generated from a signal output by an X-ray detector having a wide field of view, of the first X-ray detector and the second X-ray detector. The method according to any one of claims 1 to 3 , wherein image data is generated, and the generated scattered radiation image data is used to perform scattered radiation correction of X-ray image data generated from a signal output by an X-ray detector with a narrow field of view. 1. The X-ray diagnostic apparatus according to claim 1. The correction unit extracts a region wider than the field of view of the X-ray detector with a narrow field of view from X-ray image data generated from a signal output by the X-ray detector with a wide field of view, and uses the extracted region. 5. The X-ray diagnostic apparatus according to claim 4 , wherein the scattered radiation image data is generated by A control unit for displaying side by side a display image based on X-ray image data generated from a signal output by the X-ray detector with a wide field of view and a display image based on the X-ray image data after the scattered radiation correction. 6. An X-ray diagnostic apparatus according to claim 4 or 5 , comprising: a first X-ray detector that outputs a first signal based on X-rays emitted from an X-ray tube;
a second X-ray detector that outputs a second signal based on the X-rays in parallel with the first X-ray detector;
First X-ray image data generated from the first signal output from the first X-ray detector and second generated from the second signal output from the second X-ray detector are weighted according to the spatial resolution, signal-to-noise ratio, or motion blur after correction of the X-ray image data to be corrected, and the weighted X-ray image data are added. a correction unit that corrects the X-ray image data to be corrected;
with
The first X-ray detector and the second X-ray detector generate the first signal and the second signal over time, respectively, based on the X-rays emitted from the X-ray tube over time. output
The correction unit is generated from a plurality of chronological first X-ray image data generated from the chronologically outputted first signal and the chronologically outputted second signal By performing relatively low weighting on X-ray image data chronologically older than the X-ray image data to be corrected, among the plurality of temporal second X-ray image data, correction is performed. An X-ray diagnostic apparatus that corrects motion blur included in subsequent X-ray image data to be relatively low. a first X-ray detector that outputs a first signal based on X-rays emitted from an X-ray tube;
a second X-ray detector that outputs a second signal based on the X-rays in parallel with the first X-ray detector;
First X-ray image data generated from the first signal output from the first X-ray detector and second generated from the second signal output from the second X-ray detector are weighted according to the spatial resolution, signal-to-noise ratio, or motion blur after correction of the X-ray image data to be corrected, and the weighted X-ray image data are added. a correction unit that corrects the X-ray image data to be corrected;
with
The first X-ray detector and the second X-ray detector generate the first signal and the second X-ray detector based on a plurality of X-rays with different doses emitted from the X-ray tube over time. signals over time,
The correction unit is generated from a plurality of chronological first X-ray image data generated from the chronologically outputted first signal and the chronologically outputted second signal By giving a high weight to the X-ray image data based on X-rays with a relatively large dose among the plurality of temporal X-ray image data, the X-ray image data after correction is relatively An X-ray diagnostic apparatus that is corrected to have a high signal-to-noise ratio. a first X-ray detector that outputs a first signal based on X-rays emitted from an X-ray tube;
a second X-ray detector that outputs a second signal based on the X-rays in parallel with the first X-ray detector;
First X-ray image data generated from the first signal output from the first X-ray detector and second generated from the second signal output from the second X-ray detector are weighted according to the spatial resolution, signal-to-noise ratio, or motion blur after correction of the X-ray image data to be corrected, and the weighted X-ray image data are added. a correction unit that corrects the X-ray image data to be corrected;
with
The correcting unit adjusts the first X-ray image data or the first X-ray image data so as to match the smaller pixel size of the pixel size of the first X-ray detector and the pixel size of the second X-ray detector. 1. An X-ray diagnostic apparatus for correcting two X-ray image data and then using one X-ray image data to correct the other X-ray image data. a first X-ray detector that outputs a first signal based on X-rays emitted from an X-ray tube;
a second X-ray detector that outputs a second signal based on the X-rays in parallel with the first X-ray detector;
First X-ray image data generated from the first signal output from the first X-ray detector and second generated from the second signal output from the second X-ray detector are weighted according to the spatial resolution, signal-to-noise ratio, or motion blur after correction of the X-ray image data to be corrected, and the weighted X-ray image data are added. a correction unit that corrects the X-ray image data to be corrected;
with
The correcting unit corrects scattered radiation based on X-ray image data generated from a signal output by an X-ray detector having a wide field of view, of the first X-ray detector and the second X-ray detector. An X-ray diagnostic apparatus that generates image data and uses the generated scattered radiation image data to perform scattered radiation correction on the X-ray image data generated from a signal output by an X-ray detector with a narrow field of view.

Images